本帖最后由 开水滋养 于 2013-4-6 18:47 编辑: Q/ a7 m Y F* p
# I% j9 A1 ^$ l7 `1 HTemperature and pressure5 o7 t/ S8 R. r2 C0 B/ w2 K * ]' h* m/ n) B7 c; G! v% t The temperature of the inner core can be estimated by considering both the theoretical and the experimentally demonstrated constraints on the melting temperature of impure iron at the pressure which iron is under at the boundary of the inner core (about 330 GPa). These considerations suggest that its temperature is about 5,700 K (5,430 °C; 9,800 °F).[13] The pressure in the Earth's inner core is slightly higher than it is at the boundary between the outer and inner cores: it ranges from about 330 to 360 gigapascals (3,300,000 to 3,600,000 atm).[14] Iron can be solid at such high temperatures only because its melting temperature increases dramatically at pressures of that magnitude (see the Clausius–Clapeyron relation).[15]( K. f! D. k4 v& ?& d
# n8 l5 S! D; ]so ! z9 H4 _* [% O" @$ K! _: BThe inner core of the Earth has temperatures and pressures so great that the metals are squeezed together and are not able to move about like a liquid, but are forced to vibrate in place as a solid. The inner core begins about 4000 miles beneath the crust and is about 800 miles thick. The temperatures may reach 9000 dgrees F. and the pressures are 45,000,000 pounds per square inch. This is 3,000,000 times the air pressure on you at sea level!!! |